Interior-conduit outlet-box.



No. 7|2,5I4. Patented Nov. 4, |902.

F. W.ER|CKSUN. INTERIOR CNDUIT OUTLET BX. (Application mea mr. 2e,\19o2.)

(llo Madal.)

ngL

T5: Nonms PETERS m, Prlproruwu..wAsMmoTon. u. c.

'UNITED' srt-m` Partnr Orr-ics;

resonator: w. sRioKsoN, on Bo'sroN, MAssAcnnsE'rrs lNrEmoR-coNnUlTouTLET-sox.

SPEOLFGATIUN forming part'of Letters Patent No. 712,514, `dated November 4i; `1902- `Application tiledllliaroh 26, 1902.

semi nn. 100.050. tno moda.)

To ctt/ZZ whom, t may con/cern.' i

Be it known that I, FREDERICK W.ERICK SON, residing at Boston, in the county of Suffolk and `State of Massachusetts, have invented certain Improvements in `Interior-Conduit1 Outlet-Boxes,of which the following is a speciiication.

In the manufacture of cast-metal conduit` outlet-boxes much ingenuity has been exercised in preparing fon the orifices to which the conduits are to enter in` order that the conductors which are to be threaded through them may find their way to the switch `or other terminals .which `may be located in the.V Formerly holes were cast -or drilled in the walls of theboxes `and then plugged up duits and bushings, which ai'e `to he `broken away when a conduit is .tobe enteredinto the box. pensive-in first cost, and others, such `as the thin-wall portions boxes, are diflicult totinish after the hole has been made, and frequently the ,entire box is fractured by the blow or blows required to effect the entrance. When the thin portion has been successfully broken, the hole has to be tiled and smoothed 4to fit the end `of the conduit, and the cast iron at such places is found to be hard and difficult to work.

The present invention addresses itself to the formation of an outlet-box upon a principle entirely new, and consists in forming what may be termed cores, whose peripheries are of the exact shape it is desired the metal entrances to the box shallbe, made of some substance which has a higher meltingpoint than the metal ofthe box or formed,

from some refractory material, as earths or` clays, which are hard-baked, producing porcelain, terra-cotta, or such like products.

These cores having been thus prepared are These devices are sometimes ex'`` y. inthe casting after the metal has been poured to form the same, to be removed whenever it is desired to utilize the hole for the entrance of a. conduit, and consequently when the metal is poured into the mold it runs all around the cores the sameas -it wouldwith the ordinary7 friable cores, and as these cores are of a different or of a more refractory material the running metal does not fuse with the same or unite therewith cohesively. Therefore whenthe metal has cooled and the castingis remoged from the mold the cores are found, as it were, embedded or locked in the metal. ordinary manner, then are covered with a suitable paint orenainel, and having been pro-` `vided with suitable means for retaining a coverare ready for shipment.

Then the boxes are to be put into place in the walls of a building and the locations for conduit-entrances are determined, the ernbedded` cores, tablets, or disks are easily `broken away and the conduit-entrance is found ready for use, all of which `I will now proceed to describe, and point out in the claims.

Of the drawings, Figure lisa side sectional View of a square outlet-box embodying the in- `Ventiou. Fig. la is an end View of disk a3, and Fig. 1b is an end View of disk a4. Fig. 2 is a sectional View of a box-bushing. Fig. 3 is a plan sectional View of a round outlet-box also illustrating the invention. Fig. 3 is an end View of the plug or disk a7, and Fig. 3 is an end View of the disk a6.

. In the drawings, A representsin section a square outlet-box made from castl metal.

a, d2, a-S, and a4 are tablets or disks made from vitreous material, such as clay, and then burned or baked hard to resemble terra-cotta, porcelain, duc. Each of the disks hasupon its periphery some configuration which locks it into the surrounding metal. a. isprovided ywitha central rounded ridge 1,while its shoulders 2 slope away therefrom. a3 has a screwthread 6 upon-its periphery. a4 has a hollow 5 inits center and two projectingridges @tron each side thereof. y y

`When it is desired to enterauconduit-pipe` C into the` box, one of the fragile disksis b1oken,the parts cleaned out, and the orifice is ready. `Fig. 1b represents a side View of The castings are cleaned in the the disk a4, and Fig. 1fL is a side view of disk a3. Vhen the latter disk is broken out, a porcelain or terra-cotta insulating-bushing B (shown in section in Fig. 2) is inserted from the inside of the box. This bushing has a screw-thread 6a formed on its exterior, which is adapted to screw into the thread 6 in the box. rThis bushing is made in a mold and then baked. It has an orifice 8 of the size of an insulated conductor and an enlarged outer vpart 10, formed in the rear cylindrical part b'a and 9, the head 7 forming the abutment against the inner wall of the box.

In Fig. 3 the disk a5 has a sharp screwthread l1 on its periphery. u. is formed like a spool, with outer ends 13 and a central part 12 of less diameter. a7 is made like a plug, with a score 14 near its inner end. Its walls 16 are smooth and parallel. The hollowed-out portion l5 makes the breaking easier. Fig. 3 is a sideview of a7, and Fig. 3b is a side view of-ai. alo' has sharp screw-threads 17 and a score 18 at its inner end. Vhen this disk is broken out, there is left a screw-thread in the Vcast metal and a round ring at the inner part, `which forms a smooth surface over which the are provided with projections p on eachiside thereof, which t into the enlargements made in the mold by the core-prints on the pattern' and are thus held suspended while the metal is poured around them, precisely as are the common cores in molds.

By the method described I ain enabled to produce an outlet-box with the orifices all formed as they would be by tools of any desired shape and at the-same time have the orifices plugged until they are wanted for use and plugged with a substance which is easily and quickly broken away Without the necessity of chipping or tiling the orilice for the reception of the conduit or bushing.

I claim as my inventionl. An outlet-box cast from molten metal, provided with openings for the insertion of conduits or bushings closed with disks whose peripheries are formed into ridgesand furrows corresponding to furrows and ridges in the metal inclosing the same, the disks being made from a material not fusible with the said metal.

2. An outlet-box cast from molten metal,

provided with openings for the insertion of conduits and bushings closed with disks whose peripheries are formed into ridges and furrows corresponding to fui-rows' and ridges in the metal inclosing the same, the disks being made from an easily-fractured material.

3. An outlet-box cast from molten metal, provided with openings for the insertion of conduits or bushings closed with disks whose peripheries are formed with screw-threads, the disks being made from a material not fusible with the said metal.r y

4. An outlet-boxcast from molten metal, provided with openings for the insertion of conduits or bushings closed with disks whose peripheries are formed with screw-threads, the disks being made from vitreous material and baked.

5. An outlet-box cast from molten metal, provided with openings for the insertion of conduitsor bushings closed with disks whose peripheries lock with the surrounding metal, the disks being made from a material not fusible with the said metal.

6. An outlet-box cast from molten metal, provided with openings for the insertion of conduits or bushings closed with disks whose peripheries lock with the surrounding metal, the disks being made from a material Whose fusible point is higher than the surrounding metal.

7. An outlet-boX cast from molten metal, provided with openings for the insertion of conduits or bushings normally closed with disks whose peripheries lock with the surrounding metal, the disks being made from vitreous material and baked.

S. A metal outlet-box, provided with openings for the insertion of conduits and bushings closed with 'disks or plugs whose peripheries are formed into screw-threads corresponding to screwthreads in the metal inclosing the same, the disks made from an easilyfractured material.

9. A metal outlet-box, 'provided with openings for the insertion of bushings normally closed with disks or plugs whose peripheries are formed into screw-threads corresponding to screw-threads in the metal inclosing the same, the disks made from an easily-fractured material; with a bushing molded from clay and baked, adapted to enter one of said orifices when its disk is removed, as set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 22d day of March, 1902.

FREDERICK W. ERICKSON. Y

Witnesses:

J. L. STERN, J OHN J. ERICKSON.

IOO

IIO 

